September 30, 2011: Recently, after six years of development, the U.S. Navy successfully test fired its new 155mm AGS (Advanced Gun System) cannon. Designed for use on the new DDG 1000 ("Zumwalt") destroyers, the AGS fires GPS guided shells up to 190 kilometers. The recent test firing of two shells only went out to 81 kilometers. The GPS guidance enables the shells to land inside a 50 meter (155 foot) circle. The AGS shells carry 11 kg (24 pounds) of explosives. The AGS uses a water cooled barrel, so that it can fire ten rounds a minute for extended periods. Each AGS carries 335 rounds of ammo, which is loaded and fired automatically. The AGS shell is expected to enter service in three years.

The U.S. Army has a similar round, the Excalibur, which entered service four years ago. Excalibur has a max range of 50 kilometers and will land within a 20 meter (62 foot) circle. In practice, Excalibur will land within a few meters of where it's aimed. Each Excalibur shell carries 9 kg (20 pounds) of explosives. The AGS shell has a longer range because it is fired from a longer barrel using a more powerful propellant charge. AGS rounds are also capable of the same accuracy as Excalibur, but it depends on the quality of the GPS signal in the area.

The new AGS round replaced an earlier project, that ended in 2005, after twelve years of effort, and two billion dollars, to develop a GPS guided round for a five inch (127mm) naval gun. This ERGM (extended range guided munition) system never worked reliably. So the navy went looking for another solution. Taking note of the success of the 155mm Excalibur, the navy ended up using that technology for its AGS. The navy wants to use AGS on new warship designs, in order to get more effectiveness out of the limited amount of ammo a ship can carry. Accuracy is the key. A "dumb" (unguided) artillery shell will land with 75 meters (or more, depending on range) of the aiming point, while the laser guided Copperhead (an older army 155mm design that was too expensive) would land within a meter or two. GPS guided shells will land within 3-25 meters of the aiming point.

Excalibur has proved very popular with army troops, but with so many other guided weapons available (especially the 227mm GPS guided rocket), not many are used. In Afghanistan, 5-10 Excalibur shells are fired a week. For this reason, AGS may never be heavily used for supporting troops ashore. Adding a terminal guidance system to the AGS shell would make it suitable to attacking other ships.

Putting the AGS on a 14,500 ton $3 billion ship is ridiculous. A gunfire support ship should be well protected with a double hull for mine resistance so that it can be risked near or even inshore. Instead we've got an Aegis equipped heavy cruiser that because of it's high cost is not going to be risked near shore. AGS on this ship is quite ridiculous.

The main rationale for the ship is long range cruise missile strike. So instead of having more than 80 launch cells the two AGS (and 900 155mm rounds plus storage and handling) compete with the main mission for space and drive the size of the ship up so it's in fact too damn expensive to risk employing the 155mm. For gunfire support an economical monitor with two AGS, and very little else, on a well protected hull is what the nation needs and instead we get a 14,500 ton destroyer with a compromised but very expensive new radar system that can't do area anti air with it's ESSM's primarily armed with long range cruise missiles that gets the naval gunfire support role thrown in on top.

Putting the AGS on a 14,500 ton $3 billion ship is ridiculous. A gunfire support ship should be well protected with a double hull for mine resistance so that it can be risked near or even inshore. Instead we've got an Aegis equipped heavy cruiser that because of it's high cost is not going to be risked near shore. AGS on this ship is quite ridiculous.

The main rationale for the ship is long range cruise missile strike. So instead of having more than 80 launch cells the two AGS (and 900 155mm rounds plus storage and handling) compete with the main mission for space and drive the size of the ship up so it's in fact too damn expensive to risk employing the 155mm. For gunfire support an economical monitor with two AGS, and very little else, on a well protected hull is what the nation needs and instead we get a 14,500 ton destroyer with a compromised but very expensive new radar system that can't do area anti air with it's ESSM's primarily armed with long range cruise missiles that gets the naval gunfire support role thrown in on top.

LB, I had thoughts similar to yours, but in the end I concluded:

1. No armor can protect from anti ship missiles.

2. 80km is beyond range of the most of the land operating artillery.

So, ship could be protected from land based artillery by the range of her guns, and from anti ship missiles the usual ways, like CIWS and RAM. But, there are situations where the ship can't keep distance like when target is in deep fjords, narrow straits, etc.

By the way, Russian former Kirov class battlecruisers are still armor protected. It's not much of an armor (around 76 or 100mm thick in some places, I think), but still makes me wonder what is it for. Any ideas ?

It's not clear that modern anti ship missiles have much armor penetration or that there is public information whether 3 to 4 inches of armor will stop certain missiles from penetrating. For a ship operating near shore designed for naval gunfire support I'd suggest a double hull, possibly foam filled and/or armored to some degree, would offer significant protection against mines, missiles, and other threats.

The threat of land based artillery against an AGS equipped ship is probably the least of all threats given the ship can both maneuver and remain out range. The main threat are mines and anti ship missiles.

The problem, however, is a ship not being risked near shore means the range of it's gun(s) inland is sharply reduced. Ships doing naval gunfire support have to operate near or inshore. Operating 30 miles offshore with AGS would mean the range inland would be a max of 20 or so miles with extended range rounds. Ideally one would want to operate much closer to exploit the range inland.

If the battle space is prepared enough for troops to perform a landing and/or are already operating inland one would assume various threats have already been dealt with allowing supporting ships to operate near shore. The biggest and most persistent threat in this case are still mines thus I'd suggest a ship with the primary mission of naval gunfire support should have a double hull. A modern monitor. Monitor's in WWII were involved in every major landing in the ETO and were at times the only battleship sized guns available as the battleships were tasked for force protection. When both operated, such as for Normandy, the monitor's were more effective for two reasons. The shallower draft allowed them to operate closer to shore as well as the purpose designed shore supporting turrets allowed higher elevation than any RN BB and they could also use a higher charge.

There is nothing unique on DDG 1000 other than AGS. The USN does not lack VLS ships for cruise missiles or AEGIS equipped ships. Putting AGS on a $3 billion ship simply means the ship is less likely to be risked for NGS. Also with say 60 land attack cruise missiles it's primary mission will be long range strike which is at odds with the NGS mission.

The USN really has not properly conceptualized naval gunfire support. It's two newest ships are at odds with the mission in various ways. DDG 1000 is over equipped and too expensive and LCS doesn't have either a large enough gun or long range missiles and even the originally envisioned NLOS had too few missiles for sustained support. Calls within the USN for a proper NGS ship have been coming for decades. There's also a Congressional mandate to fill the mission. On the political level the USN can say it's tried to fill the requirement. A dozen monitors with AGS would have been far more operationally and cost effective.

I wouldn't agree that shore artillery is such a minor threat. On a clear day ship can be spotted miles away with binoculars. That's how naval battles were fought before radar. Stealth does not help in that case. Once spotted, large and unarmored vessel, probably, does not stand much chance if within range of shore battery, mobile or stationary.

I worked on a citadel protection technology a few years back, it was hugely expensive and abandoned due to a number of reasons

1) armour is now considered to be about self protection systems rather than physical barriers

2) the cost to sheath and/or clad a citadel was prohibitive - with minimal benefit

3) Pt 1 is critical as if the self defence systems are inadequate then the chances of a mobility kill due to damage to the comms farm becomes significant. mobility in this sense is how the ship can continue to participate as part of the broader operational picture as its an active node - be it sensor or shooter.

look at the structure of your typical surface action element, all are interlinked and noded up and overlap to cross support each other at a sensor level. lose one and it starts to tear at the fabric of the over all integrity of the fleet as it imposes a load on remaining assets.

the combat sympathy is about the sensors etc... self protection issues are better served by whatever gucci gear is in place - its no longer about physical kinetic stoppers and barriers

Well I didn't say it was "such a minor threat" but rather that it's the least threat to an AGS equipped ship. The main reason for this is that it's a USN ship and there are myriad other assets to deal with land based artillery and associated radars. Secondarily the range and rate of fire of AGS combined with the ships mobility provides significant advantage in counter battery, not that a USN ship is going to operate in isolation in any case.

Actually ships have traditionally operated quite well operating within range of land based artillery. Given their mobility they don't actually have to close to within range of heavily defended areas and with rare exception have not. An AGS equipped ship need not operate within visual range and thus the main factor is dealing with the other sides radars.

If you're going to invest in robust detection assets to defend your shoreline it makes a bit more sense to back that up with anti ship missiles than multiple batteries of long range artillery which have much lower hit probabilities. In any case a ship coming under this threat can maneuver away while various other assets deal with that. The main threat will continue to be mines. Mines have sunk and damaged more USN ships since WWII than anything else. They've also passively denied access to near shore much more effectively than land based air, anti ship missiles, or artillery.

That said the best defense is in fact to defend the minefield and land based artillery can play a role but I'd suggest only in part and not as the main system. Even here extended range guided artillery rounds are probably not the best anti ship investment compared to missiles. Indeed if a ship is operating within visual range long range anti tank missiles can be more effective than artillery. This all sounds good in theory of course. A USN AGS equipped ship supporting troops on shore is already operating within a very well prepared battle space and the other side is going to be best served trying to replenish a mine field with small craft and/or using anti ship missiles than trying to get an artillery batter or battalion within range.

I wouldn't agree that shore artillery is such a minor threat. On a clear day ship can be spotted miles away with binoculars. That's how naval battles were fought before radar. Stealth does not help in that case. Once spotted, large and unarmored vessel, probably, does not stand much chance if within range of shore battery, mobile or stationary.

GF I'm not familiar with what you worked on but obviously, with a few exceptions, since WWII armor has been abandoned as a means to protect warships. That said for the specific role of gunfire support a purpose built ship might be well served with a double hull with some degree of armored protection with the intent of providing the ship with a reasonable protection against mines. Any other benefits would be secondary.

If one looks at DDG 1000 it clearly has excellent self protection against air and missile threats and will not be operating alone. The main threat that would prevent it's employment for naval gunfire support, as prevented other USN ships within the past 20 years, are mines. The USN simply is not going to risk a $3 billion ship against any significant mine threat. A ship built to survive against mines would have a greater likelihood of being employed.

In any case it's not as if the USN really believes in naval gunfire support. The only ships with 5inch guns are now rather expensive and large AEGIS equipped ships and now 3 6inch equipped ships. The USN got out of brown water operations after Vietnam and really has not desired to go back and prefers to rely on naval aviation and cruise missiles. The first issue of Proceedings I picked up in the early 1970's called for a purpose built ship for NGS and almost 40 years later the requirement still exists. AGS should have put on a ship whose primary mission was NGS not secondary driving up the size and cost of an already expensive ship preventing both it's employment for NGS and being affordable enough to purchase in useful numbers.

Monitors were deemed obsolete prior to WWII and turned out to be the most effective ships for shore bombardment for a variety of reasons and participated in every major ETO landing even when battleships did not. They fired at longer range than the same guns on battleships, could get close to shore further exploiting range, were more likely to be risked and thus used, and did not have to keep a high percentage of rounds in reserve in case of surface action.

The USN has enough AEGIS ships. It could in fact use some cheaper non AEGIS frigates and cost effective purpose built ships for naval gunfire support however protected.

I worked on a citadel protection technology a few years back, it was hugely expensive and abandoned due to a number of reasons

1) armour is now considered to be about self protection systems rather than physical barriers

2) the cost to sheath and/or clad a citadel was prohibitive - with minimal benefit

3) Pt 1 is critical as if the self defence systems are inadequate then the chances of a mobility kill due to damage to the comms farm becomes significant. mobility in this sense is how the ship can continue to participate as part of the broader operational picture as its an active node - be it sensor or shooter.

look at the structure of your typical surface action element, all are interlinked and noded up and overlap to cross support each other at a sensor level. lose one and it starts to tear at the fabric of the over all integrity of the fleet as it imposes a load on remaining assets.

the combat sympathy is about the sensors etc... self protection issues are better served by whatever gucci gear is in place - its no longer about physical kinetic stoppers and barriers

Well I didn't say it was "such a minor threat" but rather that it's the least threat to an AGS equipped ship. The main reason for this is that it's a USN ship and there are myriad other assets to deal with land based artillery and associated radars. Secondarily the range and rate of fire of AGS combined with the ships mobility provides significant advantage in counter battery, not that a USN ship is going to operate in isolation in any case.

Well. it was you who suggested that ship should go as close as possible in order to reach inland as far as possible.

Yes, mines are deadly. They took heavy toll during WWI and WWII, and they have been perfected ever since. I am sure that there are some nasty surprises waiting .....

This will double the effective range of selfpropelled artillery and with at direct hit probability so great, that rangeing shots are eliminated. A direct hit from a 6" shell is a argument that is very difficult to fault.

This will augment the firepower of artillery enormeously. It is something you can only move away from. But considering russian style artillery barrages, that has been standard practice for very many years: One salvo - move - because all hell is on its way, as your grenade leaves the barrel. So even if the other side use it as well, it will only give the little guy more targets. Especially if you can locate the enemy piece by the apogee. On a front there are only so many firing positions, and even if your have three times the number of pieces you will loose a lot of time just moving around.

I have not gone into the less dependence on resupply. Not only are the demands on resupply easier

Considering naval warfare a practical range of 80 would bring the fleet out of range of the more affordable Harpoon-type mobile coastal batteries.

This explains a lot:

1) I had wondered why the new Ivar Huitfeldt-class frigates have not found the funding for full equipment suite - understandable now. Given the gunfire option much of it is not needed. Or will be purchased at a bargain price.

Even the laying of minefields in the Bay of Finland - just outside Sct. Petersburg takes on a whole new dimention. The russian fleet will not only not break out - if that is the proper term - into the Baltic Sea; They bloody well won't leave port.

2) It has been a mystery to me why the Danish Army disbanded their rocket artillery battery - I thought it was not to provoke the russians with the hypothetical threat of an artillery fired nuke. Perhaps so. But when an ordinary self propelled gun could do that job - it doesn´t make much sense.

3) I have mused why Denmark and Norway have been expending GPS guided bombs in Lybia, as if they were going out of style - they are. The Danish GPS bomb are a cottage-industry adaption of the original US system (the bastards would share the source code with us, so the data weren't downloaded from the plane; but someone found a way around that). The number of F-35 have been adjusted downward - though I don't think that is the final word.

Secondly, I think we are in for a resupply of an updated version of the GPS bomb - curtesy of Uncle Sam.

This does give reason for speculation in the Arctic.

A) I would shure as hell not whish to be stationed in Murmansk with Norwegean F-35 attacking and a couple of Nansen-class shelling the narrow inlet. This might cause obstacles to the navigation.

B) An 80 km naval gun range on a Thetis-class frigate at about 80 degrees northern latitude is one bitch not worth provoking.

Not to mention the possibility of a 6 inch gun on a Knud Rasmussen patroller i the waters north of Greenland (Knud Rasmussen IS an icebreaker) - can she take it? Well mounting the gun to the lead ballast of an icebreaker - it just might work.

The big problem will be air cover.

Oh yes this is vital information.

It does also explain some command disturbance among the generals/admirals in the Danish Forces - and the appointment of Bartels as Chief of Danish defence forces - and his appointment next year for top military advisor to the politicians in NATO.